Pre-Analytics Optimization Of Non-Invasive Plasma Specimens To Improve Kras Mutation (Krasm) Detection In Patients With Non-Small Cell Lung Cancer (Nsclc)

e22150 Background: Non-invasive KRASm testing using circulating tumor DNA (ctDNA) extracted from blood is a promising companion diagnostic option, which could enable patients with NSCLC but no available tumor sample to access more treatment options. Methods: Peripheral blood samples were collected from 34 patients with NSCLC. The impact of pre-analytical processing, including sample collection tube (EDTA vs cell-free DNA blood collection tube [BCT, Streck]), incubation time at room temperature (2 vs 72h) and centrifugation steps (single vs double spin), was investigated. The use of alternative input plasma volumes was also assessed. Recovery of DNA (QIAamp Circulating Nucleic Acid Kit) was evaluated by qPCR; KRASm analysis was performed using the Therascreen KRAS RGQ PCR kit (QIAGEN). Results: Two-way analysis of variance of log-transformed data showed sample collection tube and plasma processing time had a significant effect on DNA yield (p u003c 0.01 for both factors) with EDTA collection tubes and longer i...